China's national legislature Sunday afternoon adopted constitutional amendments, enshrining Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era into the Constitution.

The amendment, was adopted at the first session of the 13th NPC with an overwhelming majority, wrote Xi's thought into the Constitution's preamble, along with other guiding theories including Marxism-Leninism, Mao Zedong Thought, Deng Xiaoping Theory, and the Theory of Three Represents.

The historic constitutional amendment breezed through China's National People's Congress (NPC) with 2 958 in favor, two against and three abstentions despite an unusual bout of online criticism that censors have scrambled to extinguish.

Xi stood up first at the imposing Great Hall of the People in Beijing to cast his paper ballot in a red box, as delegates of the National People's Congress applauded after each vote on the constitutional amendment to lift the two five-year term limit for the presidency.The first constitutional amendment in 14 years had been expected to breeze through the legislature, which has never rejected a Communist Party diktat in its half-century of existence.

Xi, 64, has consolidated power since 2012 when he was appointed to the country's top office: general secretary of the Communist Party.

While the position has no term limits, his two predecessors both gave it up after two terms as part of an orderly process established by Deng.

But with the new amendments, he could now have a lifetime to push his goal of turning China into global economic powerhouse with a "world-class" military by mid-century.

His rise has been accompanied by tighter restrictions on civil society, with the detention of activists and lawyers, and stricter limits on the already heavily controlled internet.

While attention has focused on the term limits, the amendments also include major provisions that will engrave Xi's eponymous political mantra in the constitution and hand the Communist Party an even larger role in the country's affairs.

The Communist Party says the move merely aligns the presidency with the limit-free titles of party secretary and military chief, claiming "the masses" unanimously called for the removal of term limits.

But the proposal was kept secret until it was revealed in a state media report on February 25, a week before the legislature's opening session.

The party later disclosed that Xi had presided over a meeting of the Politburo in September during which the leadership decided to revise the constitution.

The party then sought proposals and opinions, culminating in a decision in late January to introduce constitutional amendments at the NPC.

Activists fear that removing term limits may lead to a further tightening of already strict controls on media, civil society and religion, as Xi tries to impose his highly ideological vision of socialism on every aspect of society.

Beijing-based activist Hu Jia, who says authorities forced him to leave the capital during the congress, called the amendment "illegal".

"Xi asked all people to obey the constitution, and then used the amendment to place himself above it. He used the constitution as the ultimate legal weapon that binds officials and all citizens."